marion berry canes are dying

Asked August 13, 2018, 1:03 PM EDT

Help! I have a few marion berry plants. A friend also has a couple. Some of the new canes appear to be dying. They have not been tied up. Old canes have been removed. The leaves wilt and then the canes, escpecially the biggest, longest ones,then appear to be dying. The canes do have some dark brown splotches on them. There does not appear to be insect damage or disease on the leaves. They have been watered well and regularly, Have not seen voles, but there are rats in my community garden. Have not dug down to roots. There was an excellent crop this year, and I hate to see next year's crop going away. Thanks for your help. J Jim Gorter

Multnomah County Oregon fruits and vegetables berries horticulture

5 Responses

To begin the diagnostic process, please send the following images:
- The planting area overall, which includes some of the affected plants.
- An individual affected plant.
- A close view of typical damage on an infected cane.

You can attach 3 images when you reply to this email.
If you have additional useful images, reply a second time.

Leaves wilt along the cane. Then they turn brown and the cane dies. It I a usually the longest,strongest looking cans that die.

Thank you for sending the mages. I suspect the marionberries are dying due to a soil-borne fungus disease, verticillium wilt. If so, the soil in that bed is permanently contaminated because no treatment is effective.

To make certain this long-distance diagnosis is accurate, I will re-assign your question to another Expert who has more experience with marionberries than I do.

Hi:

The fist thing I'd suggest is ensure that the affected canes are not in some way kinked or have become partly detached from the crown at the base. Especially with very long canes this can often happen. Some of the new canes do look okay, based on the pictures so unless I'm mistaken there's a mix of affected and unaffected new canes. The other thing to look for is presence of Rose Stem Girdler, which is a new pest of caneberry. This pest lays eggs on the lower 1/3 of a cane and the larvae feed inside the cane disrupting water flow to distal parts of the cane. So if you are looking at an affected cane and follow it back and find a point at which there is a raised bump and below that the leaves are unaffected, this is signs of Rose Stem Girdler and the larvae can be found inside. If this is the case, remove the part of the cane from this point and burn it. Keep in mind that blackberries have a strong ability to compensate for yield lost on removed or damaged canes and may produce a similar yield on the remaining canes. Below is the URL of some information on Rose Stem Girdler from the PNW Insect Management Handbook. Feel free to write directly to the email below with questons

https://pnwhandbooks.org/insect/small-fruit/cane-fruit/cane-fruit-rose-stem-girdler